1. 1950s - seismic refraction profiles shot across the Falklands area by the Lamont-Doherty Geological Observatory.
2. 1970s - a range of mostly academic studies, culminating in the three DSDP boreholes on the Maurice Ewing Bank; these boreholes proved the existence of potential oil source rocks in the area.
Speculative seismic data (1977 - 2001)
1. 1977-78 - two speculative, regional seismic surveys shot by Western Geophysical and GSI - some 21,652 km of data.
2. 1993 and 1994 - Geco-Prakla and Spectrum acquired regional reconnaissance speculative seismic data both south and north of the Islands respectively, with a combined total of 15,558 km.
3. 1995 - Spectrum acquired infill speculative seismic data over their original reconnaissance grid to the north of the Islands; this infill survey comprises 3,650 km of data with a five kilometre spacing between lines.
4. 1997 - Spectrum acquired a grid of seismic data over the Special Co-operation Area, infilling the original regional reconnaissance grid laid down by Geco-Prakla. These data were reprocessed by Spectrum in 2000, and provide excellent quality data over the SCA region.
5. 2001 - Lundin Oil acquired 1,250 km of seismic data over the unlicensed area immediately north of Tranches A and B in the North Falkland Basin in lieu of a well in Tranche F, but are available for purchase (from Talisman Energy) by companies interested in applying for licences in that area under the open-door licensing policy being pursued by the Government.
6. 2005 9,500 km of data collected over southern basin.
Proprietary Seismic
There are also 10,000 km of 2D and 1,400 km2 of 3D proprietary data available over the North Falklands Basin that has been collected by the licensees.
Wells drilled in the 1998 drilling campaign in North Falkland Basin
1. Six wells were drilled over an eight month period in 1998, using a shared rig on a back to back basis.
2. Technical challenges of drilling in Falklands waters were proved to be far less severe than anticipated.
3. Five of the six wells drilled had oil shows.
4. Most wells found oil within post-rift sandstones located immediately above the main source rock interval, but this reservoir was under-charged as it lies above the main regional source-seal couplet.
5. Live oil was recovered to surface from one of the Shell wells: the oil has an API gravity of 27°, and was from a thin sandstone at 3,000m.
6. Significant levels of gas were recorded in one Shell well from a deep petroleum system.
7. Sufficient was learnt about the basin and its petroleum systems to anticipate success in future operations.
8. Back to back drilling was the one major disadvantage of the FOSA sharing agreement:
» operators were sharing a single rig, with rental rate near the peak of the market, and there was no time available for analysis of well results before the next well had to be spudded;
» the problem was compounded by the fact that the drill sites had been chosen at least six months in advance;
» there was no chance to pick completely new locations, with new play concepts, based on the results of the wells as they were drilled;
» consequently, only a small number of play types were actually tested, and extensive post-drilling analysis (conducted slowly and with the benefit of hindsight) has identified several other play concepts that might have been better options for drilling.
9. New targets are located on better migration pathways than the targets tested in 1998.
10. The geology and petroleum potential of these wells has been summarised by Richards and Hillier (2000a and b).
